In recent years, medical materials utilizing various polymer materials have been studied, and they are expected to be used for membranes for artificial kidneys, membranes for plasma skimming, catheters, stents, membranes for artificial lungs, artificial blood vessels, anti-adhesion membranes, artificial skins, and the like. In these materials, a synthetic polymer material, which is a xenobiotic substance, is used in contact with a biological tissue or a body fluid such as blood. Therefore, it can be desirable for such a medical material to be biocompatible. The desired biocompatibility for a medical material can vary depending on its purpose and usage. It can be desirable for a medical material used as a material that contacts blood to have characteristics of inhibiting the blood coagulation system, inhibiting the adhesion/activation of platelets, and inhibiting the activation of the complement system (antithrombogenicity).
A medical device can be made antithrombogenic by a method in which the base member forming the medical device is covered with an antithrombogenic material, or a method in which an antithrombogenic material is fixed to the surface of the base member.
For example, JP-A-4-152952 discloses a membrane for an artificial organ or a medical device, having on the surface thereof a synthetic polymer that simultaneously satisfies biocompatibilities of inhibiting the adhesion/activation of platelets, an inhibitory effect on the activation of the complement system, and affinity with in-vivo tissues. In addition, U.S. Patent Application Publication No. 2008/0262181 (corresponding to International Publication No. WO 2005/113620) discloses a biocompatible material containing a homopolymer or copolymer that has reduced interaction with biological components such as proteins and blood cells and is highly biocompatible.